Set the Instant Pot to Sauté and heat the oil in the insert until shimmering.
Season the chicken thighs with kosher salt and black pepper. Place chicken skin-side down and sear 2 minutes, flip and sear 2 minutes, then repeat searing each side once more to brown both sides.
Pour in the vinegar and scrape the bottom of the pot with a wooden spoon to loosen browned bits.
Add soy sauce, sugar, minced garlic, and bay leaves to the pot and stir gently to combine with the browned bits and vinegar.
Seal the lid and set the valve to sealing. Cook on High Pressure for 7 minutes, then allow a natural pressure release for 10 minutes before opening.
Carefully remove the chicken to a serving platter and spoon the sauce from the pot over the pieces.
Garnish with the diced chives and serve with steamed rice or your preferred side.